Homebrew PCBs

Has anyone tried used a conductive pen such as the ITW Chemtronics
CW2200MTP for making vias conductive.  Once the via has been treated
with the pen it may be possible to solder it with a low temperature
solder.

Found this

"Curing: Tack-free in 3 to 5 minutes at room
temperature. Achieves electrical conductivity
within 30 minutes. Heat cure for 5 minutes at 250
to 300°F (120 to 150°C) for maximum conductivity,
durability and chemical resistance.

Soldering: Low temperature soldering is possible
to the heat-cured silver conductive traces if done at
350°F (177°C) for <5 seconds."

Note: Solder iron tip temperatures are most commonly between
315-371°C (600-700°F) for Sn63Pb37 and
Sn62Pb36Ag02 alloys.

It looks like we have to use a low temp solder. SnIn20Ag2.8 may work but
I have not found a source for it.





[Non-text portions of this message have been removed]

Sounds like an interesting approach - I've also use the copper foil from LaserPCB to putting traces on the bottom side of a board - works pretty darn good - still have to use the low temperature solder, but that's not a problem.

73 de Ken H>

-- In Homebrew_PCBs@yahoogroups.com, "a3v03v0" <a3v03v0@...> wrote:

>
> Has anyone tried used a conductive pen such as the ITW Chemtronics
> CW2200MTP for making vias conductive.  Once the via has been treated
> with the pen it may be possible to solder it with a low temperature
> solder.
> 
> Found this
> 
> "Curing: Tack-free in 3 to 5 minutes at room
> temperature. Achieves electrical conductivity
> within 30 minutes. Heat cure for 5 minutes at 250
> to 300°F (120 to 150°C) for maximum conductivity,
> durability and chemical resistance.
> 
> Soldering: Low temperature soldering is possible
> to the heat-cured silver conductive traces if done at
> 350°F (177°C) for <5 seconds."
> 
> Note: Solder iron tip temperatures are most commonly between
> 315-371°C (600-700°F) for Sn63Pb37 and
> Sn62Pb36Ag02 alloys.
> 
> It looks like we have to use a low temp solder. SnIn20Ag2.8 may work but
> I have not found a source for it.
> 
> 
> 
> 
> 
> [Non-text portions of this message have been removed]
>

The CW2200 pen idea is not mine.  Hero999 suggested it over at
ElectroTech in this Thread
<http://www.electro-tech-online.com/general-electronics-chat/93922-using\
-silver-loaded-paint-vias.html>  .  I would like to give it a try but
need to find a source for low temp solder 350°F (177°C).

My next project uses 44 pin TQFP's and need a method to connect the vias
under the chip that will not fall apart when the PCB is heated to
melt/reflow the solder paste.

I would like to see what would happen if one treated the hole with
CW2200 and heat cured it as suggested.  Then fill the hole with solder
paste and relfow it in oven or frypan. I know it is not low temp
soldering as suggested.


--- In Homebrew_PCBs@yahoogroups.com, "sailingto" <sailingto@...> wrote:
>
> Sounds like an interesting approach - I've also use the copper foil
from LaserPCB to putting traces on the bottom side of a board - works
pretty darn good - still have to use the low temperature solder, but
that's not a problem.
>
> 73 de Ken H>
>
> -- In Homebrew_PCBs@yahoogroups.com, "a3v03v0" a3v03v0@ wrote:
> >
> > Has anyone tried used a conductive pen such as the ITW Chemtronics
> > CW2200MTP for making vias conductive.  Once the via has been treated
> > with the pen it may be possible to solder it with a low temperature
> > solder.
> >
> > Found this
> >
> > "Curing: Tack-free in 3 to 5 minutes at room
> > temperature. Achieves electrical conductivity
> > within 30 minutes. Heat cure for 5 minutes at 250
> > to 300°F (120 to 150°C) for maximum conductivity,
> > durability and chemical resistance.
> >
> > Soldering: Low temperature soldering is possible
> > to the heat-cured silver conductive traces if done at
> > 350°F (177°C) for <5 seconds."
> >
> > Note: Solder iron tip temperatures are most commonly between
> > 315-371°C (600-700°F) for Sn63Pb37 and
> > Sn62Pb36Ag02 alloys.
> >
> > It looks like we have to use a low temp solder. SnIn20Ag2.8 may work
but
> > I have not found a source for it.
> >




[Non-text portions of this message have been removed]

--- In Homebrew_PCBs@yahoogroups.com, "a3v03v0" <a3v03v0@...> wrote:
>
> The CW2200 pen idea is not mine.  Hero999 suggested it over at
> ElectroTech in this Thread
> <http://www.electro-tech-online.com/general-electronics-chat/93922-using\
> -silver-loaded-paint-vias.html>  .  I would like to give it a try but
> need to find a source for low temp solder 350°F (177°C).

I would like to try it for vias where there was no need to solder.... sounds like it would work pretty good, but at almost $30 plus shipping.....  hmmmm, I just might have to continue to solder wires thru for vias.

I will follow this thread and see what happens.

Thanks for posting the link - interesting read.

73 de Ken H>

Your post got me thinking...what if you could make a putty/paste out of a copper or tin powder? Then squeegee this putty/paste into the holes (or perhaps inject it with a syringe) where the vias are going to be, then solder them?.....just tossing out some ideas.




--- In Homebrew_PCBs@yahoogroups.com, "a3v03v0" <a3v03v0@...> wrote:

>
> Has anyone tried used a conductive pen such as the ITW Chemtronics
> CW2200MTP for making vias conductive.  Once the via has been treated
> with the pen it may be possible to solder it with a low temperature
> solder.
> 
> Found this
> 
> "Curing: Tack-free in 3 to 5 minutes at room
> temperature. Achieves electrical conductivity
> within 30 minutes. Heat cure for 5 minutes at 250
> to 300°F (120 to 150°C) for maximum conductivity,
> durability and chemical resistance.
> 
> Soldering: Low temperature soldering is possible
> to the heat-cured silver conductive traces if done at
> 350°F (177°C) for <5 seconds."
> 
> Note: Solder iron tip temperatures are most commonly between
> 315-371°C (600-700°F) for Sn63Pb37 and
> Sn62Pb36Ag02 alloys.
> 
> It looks like we have to use a low temp solder. SnIn20Ag2.8 may work but
> I have not found a source for it.
> 
> 
> 
> 
> 
> [Non-text portions of this message have been removed]
>

----- Original Message ----- 

From: "Daniel Howard Bryant" <coloradobryant@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Tuesday, June 09, 2009 12:26 PM
Subject: [Homebrew_PCBs] Re: DIY conductive vias ?


Your post got me thinking...what if you could make a putty/paste out of a 
copper or tin powder? Then squeegee this putty/paste into the holes (or 
perhaps inject it with a syringe) where the vias are going to be, then 
solder them?.....just tossing out some ideas.


Why not find out what the board manufacturers use to plug vias in pads, and 
use that? They, presumably, know what they are doing!

Leon

Board makers use a series of baths to seed the vias and then
electroplate metal into them.   A few DIY people may do it but the
chemicals are expensive and it is rather slow. I would love to be wrong
about this.

If one could find a source for low temperature solder paste it may be
possible to treat the vias with the pen and then squeegee the paste into
the holes.   I am willing to give it a go with regular solder paste but
I do not expect it to work because I expect the high temperature to
cause the material deposited by the pen to fail.

3v0

--- In Homebrew_PCBs@yahoogroups.com, "leon Heller" <leon355@...> wrote:
>
> ----- Original Message -----
> From: "Daniel Howard Bryant" coloradobryant@...
> To: Homebrew_PCBs@yahoogroups.com
> Sent: Tuesday, June 09, 2009 12:26 PM
> Subject: [Homebrew_PCBs] Re: DIY conductive vias ?
>
>
> Your post got me thinking...what if you could make a putty/paste out
of a
> copper or tin powder? Then squeegee this putty/paste into the holes
(or
> perhaps inject it with a syringe) where the vias are going to be, then
> solder them?.....just tossing out some ideas.
>
>
> Why not find out what the board manufacturers use to plug vias in
pads, and
> use that? They, presumably, know what they are doing!
>
> Leon
>



[Non-text portions of this message have been removed]

----- Original Message ----- 

From: "a3v03v0" <a3v03v0@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Tuesday, June 09, 2009 1:37 PM
Subject: [Homebrew_PCBs] Re: DIY conductive vias ?


> Board makers use a series of baths to seed the vias and then
> electroplate metal into them.   A few DIY people may do it but the
> chemicals are expensive and it is rather slow. I would love to be wrong
> about this.

It's actually much simpler than that:

http://www.rdcircuits.com/technology.php?disp=buildup_filling

Leon

"leon Heller" <leon355@...> writes:
> http://www.rdcircuits.com/technology.php?disp=buildup_filling

Even they say they electroplate the vias first, though.

----- Original Message ----- 

From: "DJ Delorie" <dj@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Tuesday, June 09, 2009 3:09 PM
Subject: Re: [Homebrew_PCBs] Re: DIY conductive vias ?


> 
> "leon Heller" <leon355@...> writes:
>> http://www.rdcircuits.com/technology.php?disp=buildup_filling
> 
> Even they say they electroplate the vias first, though.

But it's just a single stage, not several stages as was claimed.

Leon

"leon Heller" <leon355@...> writes:
> But it's just a single stage, not several stages as was claimed.

Are we reading the same page?  They don't describe their plating
process at all on that page, just that they plate the vias before
filling, then plate over them afterwards.  I would assume that the
plating processes are the same regardless of whether you're going to
fill the hole or not.

Plugging holes is an add on to plated through holes.  As far as I know
all commercial processes seed and plate holes.

I do toner transfer. apply solder paste with a stencil, and reflow in a
fry pan (ala sparkfun).  I am just starting to use TQFP and need vias
under the chip.  If I solder wires in the vias I do not think I can use
the fry pan to reflow.

The hope is that I can metalize the walls of the vias with the pen and
heat cure.  The apply solder paste into the vias using a stencil that
has both SMD pads and vias.

Note that the pen is marketed to make and repair traces.  This falls
outside of that intended use.

3v0



--- In Homebrew_PCBs@yahoogroups.com, DJ Delorie <dj@...> wrote:

>
>
> "leon Heller" leon355@... writes:
> > But it's just a single stage, not several stages as was claimed.
>
> Are we reading the same page?  They don't describe their plating
> process at all on that page, just that they plate the vias before
> filling, then plate over them afterwards.  I would assume that the
> plating processes are the same regardless of whether you're going to
> fill the hole or not.
>

Hi guys,

Toavoid use of chemicals, could it to possible to activate the holes with cured silver paste and then use copper electro-plating to get PTH ?

Mike

--- On Tue, 6/9/09, a3v03v0 <a3v03v0@...> wrote:

From: a3v03v0 <a3v03v0@...>
Subject: [Homebrew_PCBs] Re: DIY conductive vias ?
To: Homebrew_PCBs@yahoogroups.com
Date: Tuesday, June 9, 2009, 12:37 PM











    
            
            


      
      Board makers use a series of baths to seed the vias and then

electroplate metal into them.   A few DIY people may do it but the

chemicals are expensive and it is rather slow. I would love to be wrong

about this.



If one could find a source for low temperature solder paste it may be

possible to treat the vias with the pen and then squeegee the paste into

the holes.   I am willing to give it a go with regular solder paste but

I do not expect it to work because I expect the high temperature to

cause the material deposited by the pen to fail.



3v0



--- In Homebrew_PCBs@ yahoogroups. com, "leon Heller" <leon355@... > wrote:

>

> ----- Original Message -----

> From: "Daniel Howard Bryant" coloradobryant@ ...

> To: Homebrew_PCBs@ yahoogroups. com

> Sent: Tuesday, June 09, 2009 12:26 PM

> Subject: [Homebrew_PCBs] Re: DIY conductive vias ?

>

>

> Your post got me thinking...what if you could make a putty/paste out

of a

> copper or tin powder? Then squeegee this putty/paste into the holes

(or

> perhaps inject it with a syringe) where the vias are going to be, then

> solder them?.....just tossing out some ideas.

>

>

> Why not find out what the board manufacturers use to plug vias in

pads, and

> use that? They, presumably, know what they are doing!

>

> Leon

>



[Non-text portions of this message have been removed]




 

      

    
    
	
	 
	
	








	


	
	


      

[Non-text portions of this message have been removed]

--- In Homebrew_PCBs@yahoogroups.com, "a3v03v0" <a3v03v0@...> wrote:
>
> Plugging holes is an add on to plated through holes.  As far as I know
> all commercial processes seed and plate holes.
> 
> I do toner transfer. apply solder paste with a stencil, and reflow in a
> fry pan (ala sparkfun).  I am just starting to use TQFP and need vias
> under the chip.  If I solder wires in the vias I do not think I can use
> the fry pan to reflow.

Maybe and maybe not, I've used a toaster oven to do reflow on TQFP packages and haven't had any trouble. (I got a toaster oven at a local thrift store for $7) 
In my opinion, as long as you get the wire/vias as flush as possible to the PCB under the TQFP package so that the pins rest against the pads of the PCB, you should be ok!


> 
> The hope is that I can metalize the walls of the vias with the pen and
> heat cure.  The apply solder paste into the vias using a stencil that
> has both SMD pads and vias.
> 

I think you are on to something here, and if you get good results, please let us know, because I too would like to experiment with this method.


> Note that the pen is marketed to make and repair traces.  This falls
> outside of that intended use.

Diesel engines are meant to burn diesel, but apparently you can still burn vegetable oil or peanut oil in them (with modification of course).

Why not try something new with something meant for something else? 
I wish you good luck and much fun with your experimentations!
Daniel

> 
> 3v0
> 
> 
> 
> --- In Homebrew_PCBs@yahoogroups.com, DJ Delorie <dj@> wrote:
> >
> >
> > "leon Heller" leon355@ writes:
> > > But it's just a single stage, not several stages as was claimed.
> >
> > Are we reading the same page?  They don't describe their plating
> > process at all on that page, just that they plate the vias before
> > filling, then plate over them afterwards.  I would assume that the
> > plating processes are the same regardless of whether you're going to
> > fill the hole or not.
> >
>

did anybody read this mail ???

--- On Wed, 6/10/09, Michel Baguet <bagmik@...> wrote:

From: Michel Baguet <bagmik@...>
Subject: Re: [Homebrew_PCBs] Re: DIY conductive vias ?
To: Homebrew_PCBs@yahoogroups.com
Date: Wednesday, June 10, 2009, 10:20 AM

Hi guys,

To avoid use of chemicals, could it to possible to activate the holes with cured silver paste and then use copper electro-plating to get PTH ?

Mike



      


      

[Non-text portions of this message have been removed]

On Sat, 13 Jun 2009 03:54:10 -0700 (PDT), you wrote:

>did anybody read this mail ???

Yes, but not doing plated through holes, and not planning to, I have
no opinion.  From what I remember, the commercial houses used a
graphite solution, or at one time, did.

Harvey

>
>--- On Wed, 6/10/09, Michel Baguet <bagmik@...> wrote:
>
>From: Michel Baguet <bagmik@...>
>Subject: Re: [Homebrew_PCBs] Re: DIY conductive vias ?
>To: Homebrew_PCBs@yahoogroups.com
>Date: Wednesday, June 10, 2009, 10:20 AM
>
>Hi guys,
>
>To avoid use of chemicals, could it to possible to activate the holes with cured silver paste and then use copper electro-plating to get PTH ?
>
>Mike
>
>
>
>      
>
>
>      
>
>[Non-text portions of this message have been removed]
>
>
>
>------------------------------------
>
>Be sure to visit the group home and check for new Links, Files, and Photos:
>http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
>
>
>